Flap control device for motor vehicle and frame comprising such a device

ABSTRACT

A flap control device spring driven toward open position upon actuator failure.

TECHNICAL FIELD OF THE INVENTION

The invention relates to a flap control device for a motor vehiclecomprising at least one flap and an actuator moving said at least oneflap between a closed and open position. The invention also relates to aframe comprising such a device.

PRIOR ART

It is known that motor vehicles comprise an air inlet in which heatexchangers are arranged. This air inlet can be obstructed to a greateror lesser extent by flaps which are controlled by an actuator, thisoccurring as a function of the use conditions of the heat exchangers.

These controlled flaps are used to reduce the coefficient of drag and toimprove the cooling and air-conditioning performance. However, in theevent of failure of the actuator, the flaps can be blocked in the closedposition, which obstructs the passage of air toward the heat exchangers,thus resulting in overheating of the engine.

It is also known to incorporate a return spring secured to the actuator.Thus, in the event of failure of the actuator, for example due to abreak in the electrical signals, the return spring returns the flapsystem into the open position so as to allow the flaps to let air passthrough and thus avoid overheating of the engine. However, this systemimplies that the actuator must permanently overcome the return force ofthe spring, which has the disadvantage of an oversizing of the reductiongear part and involves higher current consumption. Moreover, if theactuator should suffer a failure of mechanical nature, such as, forexample, a breakage of a reduction pinion in its gearing, thepossibility of reopening then becomes impossible, which leads inevitablyto overheating of the engine and emergency stopping.

SUMMARY OF THE INVENTION

The objective of the present invention is to solve these disadvantagesby proposing a flap control device for a motor vehicle comprising atleast one flap and an actuator moving said at least one flap between aclosed and open position. According to the invention, said flap is ableto be detached from said actuator in the event of failure thereof.

Thus, with such a device, the flap is able to adopt an open positionunblocking the air inlet. Air can thus exchange with the fluidscirculating in the heat exchangers, thus avoiding overheating of theengine and emergency stopping of the vehicle.

The change of position of the flaps can be brought about by variousfactors, such as, for example, the dynamic pressure of the air or elsethe aspiration of the motorized fan unit.

Particular embodiments according to the invention propose that:

-   -   said flap is able to be detached from said actuator in a        reversible manner in the event of failure of said actuator;    -   the device comprises a detachment means such as a movable core        securing said actuator with said at least one flap;    -   the detachment means comprising a movable core is actuated by a        solenoid;    -   the detachment means comprising a movable core is actuated by a        clutch;    -   the clutch comprises a spring made of shape memory alloy        material and a return spring which are able to move the movable        core;    -   the device comprises a connector which connects a set of flaps;    -   the connector comprised in the device is a movable link rod;    -   the device comprises a driver which controls the rotation of        said at least one flap;    -   the connector is positioned between the driver and the set of        flaps;    -   the device comprises a return means moving the connector and the        set of flaps toward an open position;    -   the device comprises at least one movable stop blocking the        movement of the movable core in order to restrict the rotation        of said at least one flap between the two open and closed        positions.

The invention also relates to a frame comprising a device as describedabove.

BRIEF DESCRIPTION OF THE FIGURES

Other features and advantages of the invention will emerge on readingthe following description with reference to the appended figures, inwhich:

FIG. 1 illustrates a partial perspective view of a frame comprising adevice with flaps according to the invention.

FIG. 2 represents a detail view of a connector connecting the variousflaps according to the invention.

FIG. 3 illustrates a schematic representation of the device according tothe invention when the actuator is in an operating state without anomalyaccording to a first variant embodiment.

FIG. 4 corresponds to a schematic representation of the device accordingto the embodiment represented in FIG. 3 following a failure of theactuator.

FIG. 5 illustrates a schematic representation of the device according toa second embodiment of the invention when the actuator is in anoperating state without anomaly.

FIG. 6 corresponds to a schematic representation of the device accordingto the embodiment represented in FIG. 5 following a failure of theactuator.

FIG. 7 represents a diagram of a third embodiment according to theinvention when the actuator is in an operating state without anomaly.

FIG. 8 corresponds to a schematic representation of the device accordingto the embodiment represented in FIG. 7 following a failure of theactuator.

FIG. 9 illustrates a partial schematic representation of the deviceaccording to one particular embodiment.

FIGS. 10a and 10b are detailed views of a clutch of the device of theinvention in two configurations of one and the same embodiment.

FIG. 11 is a sectional view of the securing means of the deviceaccording to the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 illustrates a frame 3 comprising a flap control device 1 with anactuator 2 which controls a flap 4, termed control flap, between an openend position and a closed end position.

The frame 3 corresponds to a chassis with two longitudinal sides and twolateral sides for a given thickness. The frame 3 has a rectangular shapeso that the longitudinal sides are larger than the lateral sides. Theflap control device 1 is situated in the interior area of the frame 3such that all the flaps cover the whole of the interior area of theframe 3. The frame 3 can be made of various rigid materials so as to fixthe device 1 in one position; however, certain elements such as theactuator 2 can be attached to the frame without thereby being containedin the interior area of the flap. The frame 3 can adopt other geometricshapes, such as, for example, a square or else a circle, the inventionthus not being limited to the shape of the frame 3.

The actuator 2 also controls the rotation of flaps 8, termed secondaryflaps. The actuator 2 drives the control 4 and secondary 8 flaps withthe same rotary movement defined about an axis of rotation representedby the axis A.

When the control 4 and secondary 8 flaps are in the open position asrepresented in FIG. 1, namely when they extend in a longitudinaldirection (x) and transverse direction (y) with respect to the axes ofthe vehicle, the air inlet is freed and the outside air flow can passthrough the passage of the frame 3 along the arrow F.

When the control 4 and secondary 8 flaps are in the closed position,that is to say when they extend in a transverse direction (y) andvertical direction (z) with respect to the axes of the vehicle, the airinlet is obstructed and air cannot cross the frame 3.

The invention is not limited to the number of flaps present in thedevice. In fact, it is conceivable to have a system with a single flapcovering the whole of the air inlet area.

In the device illustrated in FIG. 1, the control 4 and secondary 8 flapsare connected by a connector 6.

FIG. 2 is a more detailed representation of the connector 6. Theconnector 6 is produced here in the form of a movable link rod 7 whichmoves with a translational movement represented by the axis B with thedevice represented here in a configuration where the control 4 andsecondary 8 flaps are in an open position.

The actuator 2, under the effect of a control which may be pneumatic,electrical and/or mechanical, actuates the rotation of the control flap4 about an axis A. The control flap 4 is then driven by pivoting througha defined angle, for example within a range from 0 to 90°. The flap mayadopt two end positions, termed open and closed positions.

Either the flap terminates its travel in a position where it extends ina plane defined by the longitudinal (x) and transverse (y) axes, asrepresented in FIG. 2, this position corresponding to the open positionin which air circulates through the frame 3, or the flap finishes itstravel in a position where it extends in a plane defined by thetransverse (y) and vertical (z) axes, that is to say that the flapterminates its travel perpendicularly to the open position. Thisposition corresponds to the closed position in which the flap obstructsthe frame and where air does not circulate through the frame 3. Thecontrol flap 4 can terminate its travel in a configuration comprisedbetween these two end positions.

According to another embodiment (not shown), the invention proposes thatthe flaps extend along any plane defined by the references (x, y, z) andadopts a position comprised between the two end positions, i.e. the openposition allowing the passage of air through the frame 3 and the closedposition preventing the passage of air through the frame 3. The flapsmay change position for example by pivoting, translation or else bysliding.

The flap 4, termed control flap, following its rotation brought about bythe actuator 2, causes the connector element 6, in this case the movablelink rod 7, to be translated downward or upward along the vertical axis(z) of the vehicle. The movable link rod 7, by moving, causes thesimultaneous rotation of each flap 8, termed secondary flap, which adoptthe same rotational movement as the flap 4, termed control flap.

It is apparent here that the flap 4, termed control flap, corresponds toany flap situated between the actuator 2 and the connector 6, whereasthe flap 8, termed secondary flap, corresponds to any flap situatedbetween the connector 6 and the frame 3.

With such a device, the connector 6 causes the simultaneous opening ofthe control 4 and secondary 8 flaps of the device, thus making itpossible to enlarge the air inlet of the front face of the vehicle andthus promote the exchange between the air and the heat exchangerssituated behind the frame 3. More particularly, the movable link rod 7corresponds to a part allowing the various flaps to be secured in asimple and inexpensive manner using few parts.

The control 4 and secondary 8 flaps can be pivoted in both directionsabout the axis of rotation A. In the same manner, the movable link rod 7can be driven in both directions, that is to say in this case upward ordownward.

The device represented in FIG. 2 illustrates an actuator 2 secured tothe movable link rod 7, thus causing it to be moved translationallywithout passing via a control flap 4. Here, the actuator 2 controls therotation of a lever 24 which causes the translation of the movable linkrod 7.

Thus, the flap control device for a motor vehicle comprises at least onecontrol 4 or secondary 8 flap and an actuator 2 moving said at leastthis control 4 or secondary 8 flap between a closed and open position.According to the invention, this control 4 or secondary 8 flap is ableto be detached from the actuator 2 in the event of failure of saidactuator 2.

FIG. 3 illustrates an embodiment of the device where the control flap 4is in an open position and without failure of the actuator 2, theactuator 2 being secured to the control flap 4. FIG. 4 represents theembodiment illustrated in FIG. 3 following a failure of the actuator 2,where the control flap 4 is detached from the actuator 2.

The device 1 comprises an actuator 2 which serves to rotate the controlflap 4. The device 1 also comprises a detachment means produced, here,in the form of a movable core 10 able to move independently of theactuator 2. When the device operates without anomaly, as represented,for example, in FIG. 3, the actuator 2, under the effect of a control,controls the movement, for example by rotation, of the movable core 10and, with the control flap 4 being secured to the movable core 10, itthen adopts the same rotary movement. Here, the rotation of the controlflap 4 is not limited and the flap is able to change position under theinfluence of the actuator 2.

By way of example, the control can be pneumatic, electrical or elsemechanical.

The core 10, situated between the actuator 2 and the control flap 4, canmove independently of the actuator 2 such that, when the latter isblocked following a failure, the core 10 remains movable and is able todetach the control flap 4 from the actuator 2.

The movable core 10 is, according to the embodiment described by FIGS. 3and 4, controlled by a solenoid 12 in a direction represented by an axisC. The solenoid 12 can be monostable or bistable.

The solenoid 12 is supplied permanently by a power supply 13, that is tosay an electric current accompanied by electrical controls, allowing itto maintain the movable core 10 in connection between the actuator 2 andthe control flap 4.

In theory, as illustrated in FIG. 4, where the actuator 2 suffers afailure, such as, for example, when it is no longer supplied following ashort-circuit or following a break in the electrical wiring harness orelse following a non-functioning of the electrical control of thevehicle preventing it from moving, the solenoid 12 allows the controlflap 4 to be detached from the actuator 2. The same is true in theeventuality where an internal breakage, such as a breakage of areduction pinion, would occur in the gearing of the actuator 2.

Thus, the solenoid 12 will actuate the movable core 10 in such a waythat the latter can move independently of the actuator and thus willdetach the control flap 4 from the actuator 2.

In the embodiment where the solenoid 12 is monostable, this results in abreak in the power supply of the solenoid 13. The latter then becomesmagnetically unbalanced and adopts a position, termed release position,while orienting the movable core 10 into an end position along the axisC within the limits of the solenoid 12, as represented in FIG. 4. Thecontrol flap 4 is then detached from the actuator 2.

Some embodiments propose combining the power supply 13 of the solenoidwith the power supply of the actuator 11, or providing a power supply 13of the solenoid independent of that of the actuator 2.

In the embodiment where the solenoid 12 is bistable, the power supply 13of the solenoid determines the positioning of the movable core 10. Insuch a case, the power supply 13 of the solenoid is independent of thatof the actuator 2.

The solenoid 12, according to the device represented in FIG. 4, guidesthe movable core 10 in such a way that it remains secured to theactuator 2 in the failure-free mode. In the event of failure of theactuator 2, the solenoid 12 will then bring the movable core 10 into aposition in which it is not secured to the control flap 4.

It is also possible to conceive of a device (not shown) where thesolenoid 12 orients the movable core 10 in such a way that it remainssecured to the control flap 4 and that it is detached from the actuator2 if the latter should suffer a failure.

When the control flap 4 is detached from the actuator 2, it adopts anopen position allowing air to pass through the frame 3. The control flap4 is secured to a connector 6, the latter being attached to a returnmeans, here a return spring 16. According to an embodiment representedin FIG. 3, the return spring 16 is maintained in a compressed positionunder the action of the frame 3 and of the connector 6, here a movablelink rod 7. The latter is itself maintained in such a position by thecontrol flap 4 which itself is maintained in this position under theaction of the solenoid 12 and of the actuator 2.

During an operation without anomaly, the solenoid 12 is permanentlysupplied and maintains the detachment means, here the movable core 10,in connection between the actuator 2 and the control flap 4. The devicecan thus remain in a configuration where the control flap 4 is in theclosed position as represented in FIG. 3 or in any other positiondefined by the actuator.

Following a failure of the actuator 2, as illustrated in FIG. 4, themovable core 10 is oriented under the action of the solenoid 12 toward aposition, termed release position, of the control flap 4, which is thendetached from the actuator 2. The return spring 16 is then no longersubjected to mechanical stresses retaining it in a compressed positionand adopts a non-compressed configuration. The return spring 16 causesthe connector 6, or movable link rod 7, to move, upward here, at thesame time causing the control flap 4 to be rotated toward an openposition as represented in FIG. 4.

Another embodiment (not shown) proposes that secondary flaps 8, arrangedin connection with the connector 6, are also caused, by the movement ofthe return spring 16 and of the connector 6, to pivot toward an openposition in a simultaneous manner with the control flap 4.

Such an embodiment ensures that the flaps will adopt an open position inthe event of failure of the actuator 2. Specifically, following thefailure of the actuator 2, the control flap 4 is detached from theactuator 2 and the return means 16 returns to its initial position,causing, in its travel, the movement of the connector 6 to which thecontrol 4 and secondary 8 flaps are secured. They will consequentlyadopt a rotational movement toward the open position without outsideintervention. Moreover, as the control flap 4 is detached from theactuator 2, the return force that the spring 16 must overcome is smallerthan that of a device or the control 4 and secondary 8 flaps remainsecured to the actuator 2. The device according to the invention thusavoids the oversizing of the reduction gear part.

It is also possible to conceive of a device where the return spring 16causes the movable link rod 7 to move downward or in any other directionallowing the control 4 and secondary 8 flaps to pass from an open to aclosed position.

The device, according to the present invention, therefore has theadvantage, in a situation where the actuator 2 is faulty, of allowingthe return to a configuration where the control 4 and secondary 8 flapsare in the open position without there being a need for outsideintervention. This allowing the vehicle engine to be cooled and thusavoids overheating thereof and emergency stopping.

Another advantage of the present invention is that, in the situationwhere the actuator 2 is back to normal operation, for example followinga temporary breakdown, its control electronics allow it to return to aposition indexed to that of the movable core 10 and the control flap 4.The movable core 10, under the action of the solenoid 12, then adopts aposition where the control flap 4 is secured once more to the actuator2. The control flap 4 is thus able to be secured to/detached from theactuator 2 in a reversible manner without there being a need for outsideintervention by a mechanism which will be explained later.

FIGS. 5 and 6 represent a second embodiment, with FIG. 5 describing anembodiment without anomaly and FIG. 6 representing the embodimentaccording to FIG. 5 following a failure of the actuator 2.

The detachment means, also produced here in the form of a movable core10, is, according to the embodiment illustrated in FIGS. 5 and 6,controlled under the action of a clutch 18 in a longitudinal directionrepresented by an axis C. The clutch 18 comprises a spring 20 made ofshape memory alloy material and a return spring 22 which are able tomove the movable core 10. The clutch 18 is permanently supplied by apower supply 17.

According to another embodiment, the clutch 18 can also comprise astretched electrical wire 20 made of shape memory alloy material and areturn spring 22 which are able to move the movable core 10, thestretched electrical wire being an equivalent for the spring.

As for the embodiment with the solenoid 12, it is conceivable to combinethe power supply 17 of the clutch with that of the actuator 2 or toprovide a power supply 17 for the clutch which is independent of that ofthe actuator 2.

As illustrated in FIG. 5, the clutch 18 comprises a spring 20 made ofshape memory alloy material and a return spring 22. Within the contextof a configuration with an operation without anomaly, here illustratedwith the control flap 4 in the closed position, the return spring 22 isrelaxed and the spring 20 made of shape memory alloy material iscompressed. The spring 20 made of shape memory alloy material and theactuator 2 are permanently supplied with power. As long as the spring 20made of shape memory alloy material remains supplied with current, itkeeps its compressed shape and maintains the movable core 10 inconnection between the actuator 2 and the control flap 4 by virtue ofthe opposed force exerted by the return spring 22.

In the case where the actuator 2 is no longer supplied, such as, forexample, following a short-circuit or following a break in theelectrical wiring harness or else following a non-functioning of theelectrical control of the vehicle preventing it from moving, the spring20 made of shape memory alloy material will no longer be supplied withcurrent and, by cooling, the latter will assume its original length,which will cause the control flap 4 to detach from the actuator 2. Thesame is true in the case where an internal breakage, such as a breakageof a reduction pinion, would occur in the gearing of the actuator 2.

It is also conceivable to propose a device where the spring 20 made ofshape memory alloy material orients the movable core 10 in such a waythat it remains secured to the control flap 4 and that it is detachedfrom the actuator 2 if the latter should suffer a failure.

Just as for the embodiment described above, the device illustrated inFIG. 5 comprises a return spring 16 in a compressed position under theaction of the frame 3 and of the connector 6, here the movable link rod7.

The clutch 18 is permanently supplied and maintains the movable core 10in connection between the actuator 2 and the control flap 4 by virtue ofthe spring 20 made of shape memory alloy material. The device can thusremain in a configuration where the flaps are in the closed position asrepresented in FIG. 5 or in any other position defined by the actuator.

Following a failure of the actuator 2, the movable core 10 is orientedby the clutch 18 toward a position, termed release position, of thecontrol flap 4 and is detached from the actuator 2. The return spring 16is no longer subjected to mechanical stresses which retain it in acompressed position. It then returns toward its non-compressedconfiguration and at the same time causes the control flap 4 to rotate.

According to another embodiment (not shown), the invention proposessecondary flaps 8 connected to the connector 6 which are driven in asimultaneous manner to the control flap 4 toward an open position asrepresented in FIG. 6.

Another advantage of the present invention is that, in the case wherethe actuator 2 is back to normal operation, its control electronicsallows it to return to a position indexed to that of the movable core 10and of the control flap 4. The movable core 10 under the action of theclutch 18, once more adopts a position where the control flap 4 issecured to the actuator 2. The control flap 4 is thus able to be securedto/detached from the actuator 2 in a reversible manner.

FIGS. 7 and 8 represent a third embodiment compatible with the twoembodiments described above, the embodiment with the solenoid being theonly one represented.

FIG. 7 describes an embodiment without anomaly and FIG. 8 represents theembodiment according to FIG. 7 following a failure of the actuator 2.

The device 1 comprises an actuator 2 which controls the rotation of alever 24. The device 1 also comprises a detachment means here producedin the form of a movable core 10 able to move independently of theactuator 2. The device also comprises a connector 6 which secures thesecondary flaps 8 to the lever 24 and a return spring 16 which actuatesthe connector 6, and indirectly the secondary flaps 8, toward a closedposition where air can no longer pass through the passage of the frame3.

The lever 24 is secured to the actuator 2 and causes the secondary flaps8 to rotate. It corresponds in this embodiment to the equivalent of thecontrol flap 4. In the closed position represented in FIG. 7, theactuator 2, under the effect of an electronic control, controls therotation of the movable core 10, the lever 24 being secured to themovable core 10, then adopts the same rotary movement. The lever 24drives the connector 6, which then adopts a translational movement. Thesecondary flap 8, being attached to the connector 6, adopts a rotationalmovement following the movement of the connector 6 so as to pass fromthe position represented, closed here, to a new position, such as, forexample, the open end position or any intermediate position. Therotation of the lever 24 and of the secondary flap 8 is not limited andtherefore the secondary flap 8 is able to change position under theinfluence of the actuator 2.

With such a device, the lever 24, under the action of the actuator 2,adopts a rotational movement and, via the connector 6, simultaneouslytransmits this pivoting movement to each secondary flap 8.

The lever 24, once detached from the actuator 2, adopts a configurationwhere the flap is in the open position in which air passes through theframe 3. Specifically, the secondary flap 8 is secured to a connector 6,the latter being attached to a return spring 16. In the closed positionand in the embodiment represented in FIG. 7, the return spring 16 ismaintained in a compressed position under the action of the frame and ofthe connector 6, or of the movable link rod 7. The connector 6 ismaintained in such a position by the lever 24 which itself is maintainedin this position under the action of the solenoid 12.

The solenoid is permanently supplied with power and maintains themovable core 10 in connection between the actuator 2 and the lever 24.The device can thus remain in a configuration where the secondary flaps8 are in the closed position or in any other position defined by theactuator 2.

Following a failure of the actuator 2 and as illustrated in FIG. 8, themovable core 10 adopts a release position of the lever 24. The lever 24is then detached from the actuator 2. The return spring 16 then nolonger has mechanical stresses retaining it in a compressed position andmoves the movable link rod 7 (upward here) and at the same time causesthe secondary flaps 8 to be rotated simultaneously toward an openposition.

One particular embodiment (not illustrated) proposes that the returnspring 16 causes the movable link rod 7 to be moved downward.

The device described above is also compatible with a movable core 10which is actuated by a clutch as defined above.

FIGS. 9, 10 a and 10 b represent a fourth embodiment. The actuator 2 andthe control flap 4 have a protuberance 28 and 30 respectively. The twoprotuberances are fastened, without being connected, by a clamp 26 whichis complementary in shape to the two protuberances 28 and 30 and allowsthe two protuberances 28 and 30 to be secured.

The clamp 26 has a stretched electrical wire 20 made of shape memoryalloy material which maintains the clamp 26 in a tightened or engagedconfiguration as long as the clamp 26 is supplied with electric current.This keeps the two protuberances 28 and 30 secured, as represented inFIG. 10a . In such a configuration, the actuator 2, under the action ofan electronic control, will cause the protuberance 28 to rotate. Thisrotation then causes the clamp 26 to rotate, which simultaneously causesthe protuberance 30 to rotate. The control flap 4, being secured to theprotuberance 30, will also pivot between an open or closed position.

As long as the electrical wire 20 made of shape memory alloy materialremains supplied with current, it retains its compressed shape andmaintains the clamp 26 in connection with the protuberances 28 and 30,as represented in FIG. 10a . In the event of malfunction of the actuator2, the electrical wire 20 made of shape memory alloy material is nolonger supplied and cools. It assumes its original length and no longerexerts mechanical stresses on the clamp 26, which then disengages fromthe protuberances 28 and 30, as represented in FIG. 10b . The returnspring 22 thus allows the protuberance 30, and hence the control flap 4,to be detached from the protuberance 28 and from the actuator 2.

The protuberances 28 and 30 are represented in FIG. 9 as stars. However,it is possible to envision protuberances having other geometricalshapes, such as squares, triangles, circles with stops or any othergeometrical polygon.

Whatever the embodiment used, the device 1 comprises three stops 32, 34and 36 blocking the movement of the movable core 10 in order to restrictthe rotation of the driver, that is to say the control flap 4 or thelever 24, between the two open and closed end positions. The movablecore 10 has a movable stop 36 on its outer surface. Depending on thedegree of inclination of the driver, the movable core 10 pivots underthe action of the actuator 2, thus causing the movable stop 36 to rotateand the driver, which is secured to the movable core 10, to rotate. Thesolenoid 12 or the clutch 18 has two fixed stops 32 and 34.

The movable stop 36 present on the movable core 10 pivots between twoend positions. When the movable stop 36 comes into contact with thefixed stop 34, the latter maintains the movable stop 36, and hence themovable core 10 and the driver, that is to say the control flap 4 or thelever 24, in a fixed position. The same principle applies when themovable stop 36 bears against the fixed stop 32. When the stop 36 is incontact with the fixed stop 34, the control 4 or secondary 8 flaps arein an open position. When the movable stop 36 is in contact with thefixed stop 32, the control 4 and secondary 8 flaps are in a closedposition.

This has the advantage of limiting the rotational movement of themovable core 10 and hence of indirectly limiting the pivoting of thecontrol 4 and secondary 8 flaps. The movable stop 36 is defined so as tolimit the movement of the control 4 and secondary 8 flaps between anopen position, where the control 4 and secondary 8 flaps will ensure themaximum air passage through the frame 3, and a closed position, wherethe control 4 and secondary 8 flaps will completely obstruct the entryof air into the frame 3, thus ensuring airtightness of the device. Sucha limit can, for example, be defined by a rotation of the movable corewithin a range from 0 to 90°. This has the advantage of preventing theflaps from going beyond their two end positions.

According to one embodiment, the solenoid 12 or the clutch 18 alsocomprises a spiral spring 38 which makes it possible to return themovable core 10 to a reference state and more particularly to return thestop 36 into contact with the stop 34. The driver, being detached fromthe movable core 10, adopt an open position through the force exerted bythe return spring 16. If the actuator 2 suffers a failure at the timewhen the control flap 4 is in the closed position, with the movable core10 remaining secured to the actuator 2, the movable stop 36 remains incontact with the stop 32. The driver adopts, for its part, an openposition, that is to say a position where the movable stop 36 is incontact with the stop 34. The spiral spring 38 is able to return themovable core 10 into a position where the stop 36 comes into contactwith the stop 34. Such an embodiment makes it possible for the device 1to be repositioned in its initial configuration without outsideintervention, the control electronics of the actuator 2 making itpossible to return to an angular position indexed to that of the controlflap 4.

Such an embodiment makes it possible for the device to be repositionedin an initial configuration and to return to an operating mode withoutanomaly without outside intervention.

This is particularly advantageous in situations where the failure of theactuator 2 is due to a temporary breakdown. In this hypotheticalsituation, the driver can continue to drive by virtue of the controlflap 4 being detached from the actuator 2. If the actuator 2 starts thefunction again, the control flap 4 is able to be secured again to theactuator 2 without the user needing to intervene.

According to another embodiment (not illustrated), the inventionproposes a configuration where the spiral spring 38 is arranged on theactuator 2, in particular for embodiments of the invention where themovable core 10 remains secured to the control flap 4 and is detachedfrom the actuator 2 following a failure of the actuator 2. The spiralspring 38 allows the actuator 2 to return to an angular position indexedto that of the movable core 10 during the resumption of operation of theactuator 2.

The device is then able to be repositioned in an initial configurationwithout outside intervention by virtue of the stops 32, 34, 36 and thespiral spring 38.

It is also possible to apply the system of stops and spiral spring tothe embodiment with the clamp 26. By placing fixed stops on the frame 3,it is possible to limit the rotational movement of the clamp 26 andhence to indirectly limit the pivoting of the control 4 and secondary 8flaps.

The invention also relates to a frame 3 comprising a device as describedabove.

It must be clearly appreciated, however, that these exemplaryembodiments have been given by way of illustration of the subject matterof the invention. The invention is not limited to these embodimentsdescribed above and supplied solely by way of example. It encompassesvarious modifications, alternative forms and other variants that aperson skilled in the art may be able to conceive of within the scope ofthe present invention, and in particular any combination of the variousembodiments described above.

The invention claimed is:
 1. A flap control device for a motor vehiclecomprising: at least one flap; an actuator moving said at least one flapbetween a closed and open position, wherein said at least one flap isable to be detached from said actuator, in a reversible manner, in theevent of failure of said actuator; a connector which connects a set offlaps including the at least one flap; a connecting rod operablyconnected to the at least one flap; and a spring longitudinally alignedwith the connecting rod and configured to bias the connector and the setof flaps toward the open position.
 2. The device as claimed in claim 1,further comprising a detachment means comprising a movable core securingsaid actuator with said at least one flap.
 3. The device as claimed inclaim 2, wherein the detachment means comprising a movable core isactuated by a solenoid.
 4. The device as claimed in claim 2, wherein thedetachment means comprising a movable core is actuated by a clutch. 5.The device as claimed in claim 4, wherein the clutch comprises a springmade of shape memory alloy material and a return spring which are ableto move the movable core.
 6. The device as claimed in claim 1, whereinsaid connector is a movable link rod.
 7. The device as claimed in claim1, further comprising a driver which controls the rotation of said atleast one flap.
 8. The device as claimed in claim 7, wherein saidconnector is positioned between the driver and the set of flaps.
 9. Aframe having a device as claimed in claim 1.